Gene on Chromosome 6 likely culprit in language, speech and reading problems
A gene that has been associated with dyslexia has now been linked to another persistent disability that first surfaces in childhood – Specific Language Impairment.
LSI investigator Mabel Rice was the first to report that a variant in a gene on Chromosome 6 -- KIAA0319 -- is a likely culprit in Specific Language Impairment (SLI). Children with SLI, which affects about 7 percent of 5-6-year-olds, have no other developmental disorder, hearing loss or brain injury but are late to begin talking. When they do talk, they use simpler sentence structure and immature grammar. Some also develop reading problems.
The finding is important because it shows that genes can affect language development and that other problems – such as speech production disorders and reading delays – are, in all likelihood, related.
Rice and a team of researchers from across the globe studied 322 individuals, including children with SLI, their parents and other family members. Participants completed diagnostic tests to determine the presence of SLI behavioral traits. Their genetic code was then scanned to identify mutations that family members had in common.
They found that variations in KIAA0319 had a strong effect on SLI language traits, dyslexia and speech sound disorders--problems that persist throughout adulthood. “It’s an exciting time because we’re beginning to see discoveries that have been 10 years in the making,” Rice said.
She emphasized that families should know that while SLI traits may be inherited, early intervention can offset its impact on language development and reading.
The study was published in the August 2009 Journal of Neurodevelopmental Disorders.